The present disclosure relates to a power supply system including a Battery Energy Storage System (BESS).
Since electrical energy is easily transferred and converted, it is widely used. In order to use such electrical energy efficiently, a BESS is used. The BESS receive power and is charged. Additionally, when power is required, the BESS supplies the power by discharging charged power. Through this, the BESS supplies power flexibly.
In detail, when an electricity generation system includes a BESS, it operates as follows. When a load or a system is overloaded, the BESS discharges stored electrical energy. Additionally, when a load or a system is lightly loaded, the BESS receive power from an electricity generation device or system and is changed.
Additionally, if the BESS exists independently regardless of an electricity generation system, the BESS receives idle power from an external power supply source and is charged. Additionally, when a system or a load is overloaded, the BESS supplies power by discharging charged power.
The BESS includes a plurality of battery racks connected in parallel. The battery rack includes a plurality of modules connected in series. Each of the plurality of modules includes a plurality of cells connected in series. A charging state of each of the plurality of modules varies according to charging and discharging of a battery energy system. As a charging state of each of the plurality of modules varies, the efficiency of power supplied by the BESS is reduced. Accordingly, an electricity generation system for managing the BESS efficiently is required.